The objectives of the proposed research are to isolate from Compositae new compounds which have antitumor and other biological properties. Emphasis will continue to be placed on sesquiterpene lactones, many of which have exhibited cytotoxic and carcinostatic activity in the past, so that a wider spectrum of compounds can be provided for testing. The chemistry of the compounds will be studied in order to establish their structure. New compounds will continue to be submitted to the antitumor screen of Drug Research and Development, Division of Cancer Treatment., National Cancer Institute and to other programs for drug evaluation. Since sesquiterpene lactones have shown primise as taxonomic markers, the results may also be useful for the clarification of phylogenetic relationships within Compositae.